Published online by Cambridge University Press: 17 March 2011
Deuterium dilution instead of hydrogen has been studied in microcrystalline silicon growth using plasma enhanced chemical vapor deposition with monosilane. It was found that the crystallinity for D2 dilution is significantly improved as compared to that for H2 dilution at the same growth rate. Optical emission spectroscopy measurement shows that the electron temperature of SiH4 + D2 plasma is lower than that of SiH4 + H2, indicating that the bombarding ion energy is reduced for D2 dilution. It was also found that the H-D exchange reaction on the surface has a certain threshold number of events and that microcrystalline formation occurs only above the threshold. The role of atomic hydrogen originating from a diluent in crystal formation is discussed.